The present invention relates to apparatuses and methods for monitoring health of animals, and, more particularly for monitoring the health through estimation of thermoregulation ability based on a combination of the animal's skin temperature, ambient temperature and activity level.
When animals, including pets such as dogs and cats, are sick they tend by their natural survival instinct to hide their symptoms and weakness. This behavior makes detection by the caretaker of the disease or condition of the pet significantly more difficult. Usually, by the time a pet reaches the veterinarian its medical condition is already advanced.
Veterinarians commonly apply standard medical protocols to assess the health condition of a patient. Measuring vital signs, including rectal temperature, is an essential part of such protocols. Rectal temperature serves as an indication of the patient's core body temperature and thermoregulatory ability and as such helps to detect development of disease conditions, evaluate their severity and monitor response to treatment.
Early detection of core body temperature changes is important in animals since it allows timely, and sometimes life-saving, interventions in acute situations such as heat stroke, hypothermia, and acute infections. Moreover, certain populations of pets benefit significantly from more frequent temperature measurements and their medical treatment dramatically improves. Examples of such populations include dogs and cats undergoing chemotherapy, hospitalized pets at risk of contracting an infection and those receiving immune-suppressive medications. Early and accurate detection of changes in core body temperature in these pets have been shown to correlate with improved survival and longevity.
In veterinary medicine, estimation of core body temperature and thermoregulation capacity is routinely done by a slightly invasive method, using standard over-the-counter human thermometers, inserted into the animal's rectum for several seconds. It is well known that rectal temperature does not always accurately imply core body temperature, but for practical reasons, and lack of suitable alternatives, it is the accepted clinical standard. However, measurement of rectal temperature is uncomfortable for the animal and occasionally difficult to perform if the pet animal is not cooperative, which is especially true for cats. Moreover, in some clinical situations rectal measurement becomes impossible, for example if some disease, wound or surgery is affecting the rectal area and preventing access. For practicality reasons, it is only rarely done by owners in a home setting. The result of these practical limitations is that temperature measurements on pets are performed less frequently than desired or required, even in the hands of professionals in a vet clinic or hospital, leading to a lower level of medical monitoring and care for pets.
Alternative, non-invasive techniques to measure temperature, like infra-red ear or skin thermometers, were found in clinical studies to be inaccurate, inconsistent, and unreliable. On the other hand, there is some use of invasive temperature sensors that are swallowed by the animal and transmit data while passing down the animal's intestines. The use of these devices is limited to research facilities. The cumbersome and sometimes difficult rectal method is therefore the one used clinically today.
Several attempts have been made to construct systems for remote monitoring of the animal's temperature. Such prior art systems typically require ingestible or implantable devices which make these systems unsatisfactory for the task of monitoring the pet animal. For example, battery life of ingestible devices can hardly be of appropriate duration because of strong dimension limitations defined by typical size of the pet animal.
There is a compelling need to have an apparatus and method that will provide early detection of temperature changes of pet animals such as dogs and cats, and to do so accurately and efficiently without interfering with the comfort and normal behavior of the animal. It would be particularly helpful if there was a way to measure core temperature continuously, remotely, non-invasively, accurately and reliably.